Mitochondria and lysosome-targetable fluorescent probes for HOCl: recent advances and perspectives

Hypochlorous acid (HOCl), as one of the reactive oxygen species (ROS), plays an important role in the destruction of pathogens in the immune system. However, abnormal concentration of biogenic HOCl can also damage host tissues, and it has been shown to be associated with many diseases. Accordingly, detection of HOCl at the subcellular level is important for understanding inflammation and cellular apoptosis. Toward this end, in the past few years, a wide variety of fluorescent HOCl probes have been engineered and applied for imaging of HOCl in subcellular organelles. In this review, we highlight the representative cases of the fluorescent HOCl probes with mitochondria and lysosome-targetable ability. The discussion includes their design strategies, sensing mechanisms, and applications in bio-imaging of HOCl in mitochondria and lysosomes.